muffler problem

[bonbrulin]

Hello. I own an 89 ford festiva, 2 door, carbed and manual tranny. I started replacing the rotten exhaust all the way from the front pipe including the catalytic converter right back to the muffler. I recently bought a used catylitic converter from the wreckers. Good shape, however when i went to do the work, saw that the used cat i bought had no pipe coming out the side of it like my old cat has. The pipe goes up to the side of the carb, beside another pipe that goes down to the front and into the pipe that looks to be going into the rad. I wish to know if this pipe is critical for proper running of the engine. What does this pipe do anyways? The old cat is still good, except the outer heat shield is totally shot and a bracket missing on the front to bolt onto the front pipe. If i have to, i can reuse the old cat by taking the heat shield off the cat i bought from the wreckers, and try to get the bracket off also. It was the bracket that was missing that convinced me i needed a new cat. Maybe the muffler shops have brackets and i need to return the new cat? Likely won't pass the safety without a heatshield on the cat, will it? Help me if you can, please.

[Dave G]

Heat shields? We don't need no stinkin' heat shields! :-)

[roycehof]

Yep - Those heat sheild go as soon as somebody complains about a rattling noise - Tear them off and throw it away. If it doesn't rattle leave it alone. Some catalytic converters have a separate air input tube that an air pump (or some other positive air displacement device - PULSE system, for example) will pump air into to help complete any unburned combustion products. Typically, the pipes are on the replacements and plugged unless you need them. Then you unplug it and hook it up. I don't think my 93 festiva has a tube on it. Carbed models may have though -don't know. Typically this does not make a big enough difference to fail the emission tests (especially if the car is well tuned). Good Luck

[WmWatt]

Carburetted Festivas have a pulse air system attached to the driver's side of the air cleaner. Two large diameter hoses lead down under the vehicle.